Closing the gap between energy-efficient building design and actual energy performance

January 19, 2024

In the built environment, we often see a discrepancy between the theoretical energy efficiency of buildings and their actual performance. This performance gap can be caused by a broad range of factors, from flawed installation of energy-efficient technology to ineffective operational controls or occupant behaviour that compromises efficiency.

Buildings are one of the largest contributors to greenhouse gas emissions worldwide. In Australia alone, the built environment is responsible for nearly 25% of total emissions. These figures highlight the urgency of making substantial headway toward meeting the promises of efficient building performance, especially considering national commitments to emissions reduction targets.

The Intergovernmental Panel on Climate Change has already warned that we are on track to exceed the 1.5-degree threshold without prompt action, which makes the performance gap in the built environment an even more urgent challenge. In this article, we’ll explore the regulatory and technology tools that can help building owners close the gap before time runs out.

What is the energy performance gap?

The energy performance gap is the difference between predicted energy use and actual consumption under real operational circumstances. This gap varies by building, but in some cases, it can be significant.

The energy performance gap is a significant barrier to Net-Zero goals, as building energy consumption is often markedly higher than the consumption levels predicted by performance models. This gap has been observed in both new construction and building energy retrofit projects. According to the International Partnership for Energy Efficiency Cooperation, it’s also a global issue. A recent report stated boldly:

“The performance gap is not a result of codes or regulations in any single jurisdiction, but a systemic problem globally.” 

On average, buildings consume 25% more energy in operation than what was modelled during the design process—and some buildings consume as much as 250% more energy than predicted.

Successfully bridging this gap will be a critical step toward delivering on ambitious emissions reduction goals. The Green Building Council of Australia (GBCA) is at the forefront of this effort, working toward making zero-carbon buildings the norm by 2030 and achieving net-zero operations for all buildings by 2050. 

Two NABERS tools can help close the gap

Many factors can contribute to a gap between a building’s promise and its actual performance. Building occupant choices, controls that don’t work as expected, and the failure to fine-tune a building’s operation during the first few years can all be contributing factors. 

Fortunately, NABERS has created two tools to help close the gap between efficient building design and actual energy performance: the NABERS Commitment Agreement and Agreement to Rate.

NABERS Commitment Agreement

A NABERS Commitment Agreement is a contract initiated at the design stage by developers or building owners. The contract commits the signatory to achieve a specified NABERS Energy rating for new builds, refurbishments, and various building types. 

These agreements are highly effective, as evidenced by the GBCA's report showing that 91% of buildings with both Green Star ratings and NABERS Commitment Agreements meet or exceed their energy targets, with 98% reaching these targets at peak performance. 

This success is attributed to requiring performance modelling under diverse, realistic scenarios, ensuring that buildings consistently meet their target NABERS rating. Once certified, developers can market their buildings with a specific NABERS Energy rating.

Agreement to Rate

The Agreement to Rate serves as a streamlined alternative to the NABERS Commitment Agreement by focusing on evaluating building operations post-construction. Signed at the design stage by developers or owners, it commits to obtaining a NABERS rating once the building is operational without specifying a target performance level.

This agreement can complement a NABERS Commitment Agreement or be used independently. It is applicable to various NABERS ratings, including Energy, Water, Indoor Environment, Waste, and Embodied Emissions, offering a cost-effective solution without the need for design-phase modelling or mandatory independent reviews at the design stage.

However, it prohibits marketing a specific NABERS rating during the design phase and is most effective within a policy framework that includes checks and compliance measures.

Building analytics: another tool to help close the gap

NABERS has proven that transparent measurement and disclosure of operational energy consumption drives better performance. Once a building reaches the operational stage, CIM’s PEAK Platform can help close the energy performance gap by empowering property teams with actionable insights from their building data, driving efficiency and sustainability goals for the long term.

Here are a few of the benefits building owners and REITs have seen after adopting PEAK:

  • Transparency and accountability: PEAK enables a clear understanding of the root causes and impact of inefficiencies across multiple assets, empowering onsite teams to resolve operational inefficiencies quickly and effectively.
  • Visibility and control: PEAK offers a high-level view of operational data across multiple buildings, providing an unprecedented level of insight and control over energy consumption across a portfolio.
  • Collaboration and improved decision-making: By automating workflows, PEAK streamlines operational decision-making and accelerates completion of key tasks by integrating teams on a single platform, enhancing productivity and clarifying communication.
  • Reduced energy consumption: As a building analytics and performance optimisation tool, PEAK shines brightly as a path to reduced energy consumption. The platform collects data from building equipment and sensors, leveraging advanced algorithms to transform that data into actionable insights for property management teams. PEAK proactively identifies potential equipment failures, allowing teams to adopt predictive maintenance. PEAK also helps optimise energy usage by flagging inefficiencies and identifying opportunities for reduced energy consumption and cost.
  • Water and indoor environment monitoring: PEAK also works beyond energy consumption, monitoring factors like water usage and indoor environment scores. PEAK’s Indoor Environment module tracks thermal comfort and relative humidity in real time across all zones, floors, and tenancies. This helps keep tenant satisfaction high without compromising on energy-saving initiatives. 

PEAK in action

LaSalle, a CIM PEAK customer, used a NABERS Commitment Agreement and PEAK to achieve record levels of efficiency for energy and water consumption at Transport House, a 1970s office tower in Brisbane. Driven by a NABERS Commitment Agreement to achieve a 4.5-star energy rating, LaSalle transformed Transport House from a zero-star asset into an energy-efficient workplace. 

Emily Wills, the Asset Manager responsible for Transport House, spoke about PEAK as contributing to the building’s evolution from outdated to efficient:

“Each of the floors is now separately metered, and we have a smart building analytics platform [PEAK] to drive proactive management. We can monitor the data and uncover issues in real time, and then we have the people on the ground who can proactively follow up.” 

LaSalle has found value beyond progress toward their energy performance commitments, too. The building can now be marketed as sustainable, which has proven attractive to tenants and increased the overall asset value. 


In its report on closing the performance gap in Australia’s commercial office sector, the GBCA found that the NABERS Commitment Agreement is far more than a piece of paper; it’s “a critical success factor in translating design intentions into real-world outcomes.”

The report also found that monitoring and managing building data can further reduce the performance gap, helping building owners achieve their NABERS commitments and adhere to net-zero targets. 

While the path to Net Zero is hardly a foregone conclusion, NABERS and PEAK are two proven methods to help bridge the energy performance gap.

Ready to transform your building operations? Watch a demo to see PEAK in action.

Chris Joannides
January 19, 2024